1. Field of the Invention
The present invention relates to a cover closing and reopening apparatus, and more particularly to the apparatus of the kind that finds its application or use in any surface finishing machine having a removable cover-equipped container as one of its essential elements, and includes means whereby the cover can be tightened to or released from the container for its closing or reopening operations.
2. Description of the Prior Art
The conventional apparatus that provides the automatic closing and reopening operations for a cover which is removably mounted to the container used in a surface finishing machine includes a tightening member that releasably fastens the cover to the container. The tightening member has a pivotable or rotatable pawl at one end and a stationary or fixed pawl at the other end. The tightening member is operated by means of its operating member, which engages the central bore provided in the tightening member. Rotating the operating member tightens the cover to or releases it from the container through the rotating and stationary pawls which engage or disengage the flanged edges of the container. The construction of this apparatus and its operation are described in the Japanese Utility Model Official Publication No. 50 (1975)-36269, which is opened for public examination.
The apparatus that is constructed as mentioned above provides safety in operation and is effective in fastening the cover to the container tightly. It is also noted, however, that the operation that takes place for the cover mounting or demounting involves several steps. For the mounting operation, for example, the stationary or fixed pawl at one end of the tightening member is first made to engage the corresponding lateral flanged side of the top opening of the cover by moving the tightening member to place its one end in that position, and then the rotatable pawl at the other end is rotated so that it can be made to engage the corresponding flanged side. The demounting is done by reversing the above operation. This multiple-step operation makes the automatic operation difficult, lowering the total efficiency.